1. Field of the Invention
The present invention generally relates to point-of-sale or POS terminals. More particularly, the present invention relates to POS terminals in which a personal computer is employed as a control device for controlling a printer and any other peripheral equipment.
2. Description of the Background Art
Typically, a point-of-sale or POS terminal includes an input unit for accepting keyed or scanned data from sales personnel. Such data typically includes the name or type of product along with its selling price. The POS terminal may also comprise a control unit for generating data for display or to be printed in accordance with the data entered by the sales personnel. The conventional approach is to provide a dedicated POS terminal integrating all of these devices. The disadvantage to this approach is that such devices lacks versatility and expandability. As a result, these devices are less versatile and cannot conform to the changing needs of the user. Accordingly, the demand for these dedicated POS terminals is smaller, resulting in reduced production volumes. Consequently, manufacturer can not take advantage of large scale manufacturing economies, and these POS terminals tend to be high in cost. Moreover, such disadvantages become obstacles against computerization in the POS field.
In an attempt to solve the above-discussed problems, more efforts are being made toward the development of POS terminals that utilize general-purpose computers or, more specifically, personal computers (PC's), as the control unit. These systems are referred to as PC-POS systems, and the display module and printer are connected to the PC via a general-purpose interface. In a PC-POS system, the same hardware can be configured for various types of applications by employing the appropriate software. Furthermore, by using a commercially available printed circuit board set, the PC that makes up the control unit can be configured inexpensively, and its functions can be easily expanded. Therefore, PC-POS systems are quite effective for computerizing the POS field.
A POS terminal is usually installed inside a store, particularly on a counter where accounting transactions take place. As such, the counter space occupied by the POS terminal should be as small as possible. Accordingly, the inventors have developed a PC-POS system based on a novel concept, which reduces the area occupied by the POS terminal through a design in which the control unit is housed inside a body frame possessing the same footprint as the printer, allowing the placement of this body frame below the printer.
FIG. 13 illustrates a connection of a conventional PC-POS with a general-purpose interface provided in the PC. As shown therein, the conventional PC-POS terminal comprises a control unit or device 62, a display unit or module 60 and a printer 61. In this configuration, control unit 62 provides data to display module 60. Display module 60 is equipped with a pass-through function. In other words, the pass-through function of display unit 60 does not forward a command data or display data sent by control unit 62 to printer 61, if the command or the display data is intended only for the display module itself. Alternatively, display unit 60 sends the command or print data to printer 61, if the command or print data is intended for printer 61. As shown in the FIG. 13, in this type of PC-POS terminal, the data from control unit 62 is input into display module 60, and the data output by display module 60 is then input into printer 61. The decision as to whether the data from control unit 62 should be displayed on display module 60 or printed by printer 61 is made by sending device selection data, along with data such as the total price, from control unit 62. This device selection data is recognized by either display module 60 or printer 61, and the data is displayed or printed. In this way, control unit 62 can control both a display module and a printer using a general-purpose interface.
In such a PC-POS system, because display module 60 relays the interface signals from a host computer, i.e., control unit 62, to printer 61, the interface cable connecting control unit 62 to printer 61 first connects control unit 62 to display module 60, and then connects display module 60 to printer 61. Consequently, in view of this connection cable it is difficult to stack control unit 62 and printer 61, or otherwise place them together. Furthermore, when control unit 62 and printer 61 are placed together the connecting cable has a tendency to form a loop or coil. As such the cable is prone to external electrical noise and may lead to errors in printing operation.